weedpharma is right, a crimped connection for terminals is usually superior to a soldered connection.
25+ years ago I worked in a nuclear power plant, soldered connections were not allowed, they had to be crimped.
To form a proper crimp the entire end of the wire and the crimp barrel are basically cold welded together in a homogenous, gas tight "lump" with zero gaps.
Now that being said 99% of us don't have the correct tools to do a proper crimp.
So soldering is ok for non critical, as in not aerospace, marine or nuclear, connections.:thumbsup: